1. Field of the Invention
The present invention relates to an electrophotographic photosensitive drum for use in a copier, printer and the like adopting an electrophotography system, a process cartridge employing the electrophotographic photosensitive drum and an electrophotographic image forming apparatus using the same.
2. Description of Related Art
The electrophotographic image forming apparatus forms an image on a recording medium using the electrophotographic-image-forming system. Then, the electrophotographic image forming apparatus includes, for example, an electrophotographic copier, an electrophotographic printer (e.g., a laser beam printer, an LED printer and the like), a facsimile unit, a word processor and the like.
The process cartridge is a cartridge in which charging means, developing means or cleaning means as process means is integrated with the electrophotographic photosensitive drum and this cartridge is attachable to/detachable from the electrophotographic image forming apparatus main body. At least one of the charging means, the developing means and the cleaning means as process means is integrated with the electrophotographic photosensitive drum so as to form a cartridge, which can be attached to/detached from the electrophotographic image forming apparatus main body. Alternatively, at least the developing means as process means is integrated with the electrophotographic photosensitive drum so as to form a cartridge, which can be attached to/detached from the electrophotographic image forming apparatus main body.
Conventionally, the image forming apparatus using the electrophotographic-image-forming process adopts a process-cartridge system in which the electrophotographic photosensitive drum and the process means, which acts on the electrophotographic photosensitive drum, are integrated so as to form a cartridge, which can be attached to/detached from the image forming apparatus main body. Because this process-cartridge system allows a user himself to carry out its maintenance without help of service personnel, the operability of this apparatus can be improved remarkably. For the reason, the process-cartridge system has been widely used in the image forming apparatus.
In such a process cartridge, its photosensitive drum is constructed so that flanges are fixed on end portions of a cylindrical electro-conductive body having a photosensitive layer provided on the surface thereof. The cylindrical electro-conductive body and the flanges are coupled firmly through caulking by bending part of the cylinder inwardly. Further, the photosensitive drum is journaled by a bearing disposed at a predetermined position of the cartridge casing such that it is capable of rotating integrally with a supporting shaft that is supported rotatably. Drive transmitting means, which receives a drive force from the image forming apparatus main body to rotate the photosensitive drum, is provided at an end of the supporting shaft.
The present invention is an advancement on the conventional technology.